Extension-table



T. B. HENNESSY.

EXTENSION TABLE.

No. 335,453. Patented Feb. 2, 1886.

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UNITED STAT S ATENT Fries.

THOMAS E. HENNESSY, OF CHICAGO, ASSIGNOR TO SAMUEL DINGEE, OF \VILMETTE,ILLINOIS.

EXTENSION-TABLE.

SPECIFICATION forming part of Letters Patent No. 335,453, dated February2, 1886.

(No model.)

To (til whom it may concern.-

Be it known that I, THOMAS B. HENNEssY, of Chicago, in the county ofCook and State of Illinois, have invented certain new and useful 5Improvements in Extension-'lables; and I do hereby declare that thefollowing is a full, clear, and exact description of the invention,which will enable others skilled in the art to which it appertains tomake and use the same, reference being had to the accompanying drawings,and to letters of reference marked thereon, which form a part of thisspecification.

The object of my invention is to provide means for keeping the slidingbars ofextension- 1 tables closely together, and to avoid thepossibility oftheir locking by reason of the swelling of the wood.

In the drawings, Figure 1 is a side elevation of one of the slidingbars. Fig. 2is a plan view of the same. Fig. 3 is a vertical transversesection taken on the line a 00, Fig. 2. Fig. at is a perspective view ofa couple of bars in position to be united. Fig. 5 is a detail viewshowing in perspective the spring-plate; and Fig. 6 is a detail viewshowing the tenon and spring-plate attachment.

' Reference being had to the drawings, A and B represent sliding barsprovided with longitudinal T grooves ormortises a, and provided at oneend wit-h a tenon, C, which closes said mortises at one end of said bar.That part of the body of the tenon C which is within the mortisecorresponds in shape-thereto; but the part thereof that projects fromthe bar is minus the flanges which would convert it into a T- shapedtenon, and adapt it to fit snugly the T-mortise of the engaging slidingbar B. The top of this tenon O is inclined or beveled from or near itsouter end to its inner end, and secured to said inclined surface is aspring-plate, D. This plate D extends beyond one or both of the verticalsides of the tenon O a distance corresponding to about the depth of thelateral grooves of the T-mortise of the engaging bar 45 B. Thus, asshown in Fig. 4, as the tenon is inserted into the T-mortise of theengaging bar the side edges of the plate D will enter the lateralgrooves of the same and hold the two bars closely together. If desired,the bev- 50 cling of the tenon may be dispensed with, and

the plate D extended a suitable distance in front of the inner end ofthe tenon, and bent downward slightly, so as to have about the samedeclination as the bevel of the tenon, as

hereinbefore stated. 5 5

The spring-plate D is secured to the tenon 0, preferably by a screw, d,which passes through a suitable aperture near its outer end and into thetenon. In order to prevent the plate from oscillating, I make a V-cut init, preferably between the screw d and the outer end of said plate, andthen turning the bradb thus formed downward drive itinto the tenon, asshown. A small screw or nail will answer just as well. and can beused-instead ofthe brad 6- b, if desired.

In order to facilitate the entrance of the inner or advanced edges ofthe spring-plate D intothe lateral grooves of the T-mortise a when thebars are being united, as shown in Fig. 4, 70 and to insure an easymovement of said edges in the grooves, I curve the corners ccnpwardslightly. If the wood of which the barsAand B and the tenons G are madeswells vertically, because of the prevalence of moisture, thisspring-plate D will give suificiently to accon1- modate this swelling.In order to accommodate any lateral swelling, I can make the tenonnarrower than the groove it enters. In Fig. 5 is shown a modified formof this plate D. It has lateral cuts made near its innerend, formingleaves 6 e, which are turned downward. This plate is secured to thetenon in such position that the leaves 6 0 will be in advance of thetenon, and. will press outward against the sides of the mortise in whichit moves, thus accommodating any lateral swelling of the wood. Thecorners left by the forming of leaves e a may be turned slightly upward,if desired, as shown. 9C

The construction of the sliding bars I lay no claim to, but suffice itto say their construction and operation are the same as those now incurrent use.

I am aware of the existence of Letters Patent No. 257,274, granted May2, 1882,in which the tongue is made entirely of wood, havingalongitudinal oblique slot in it to give it spring, and also of LettersPatent No. 183,276, granted October 17, 1876, in which the tongue isdivided centrally at right angles to the bottom of the groove, and arubber cushion or a metallic spring placed between the divided parts.

My invention differs from the construction of the patented inventionsreferred to in details hereinbefore described and illustrated, and aspointed out in the claims.

What I claim as new is 1. The combinatiomwith the sliding bars ofextension-tables having longitudinal mortises in their engagingsurfac'es,of the tenons adapted to enter said mortises, and the metallicspring'plate D, said plate having the corners of its advanced or innerend slightly curved upward.

2. The conibination,with the sliding bars of extension-tables havinglongitudinal mortises in their engaging surfaces, of a tenon having itsinner end tapered or beveled, and the metallic springplate D, secured tosaid tenon.

3. The combination, with the sliding bars of extension-tables havinglongitudinal mortises in their engaging surfaces, of the tenons adaptedto enter said mortises, and the metallic spring-plate D, substantiallyas set forth. 25

4. The combination, with the sliding bars of extension-tables havinglongitudinal grooves in their engaging surfaces, of the tenon 0,metallic spring-plate D,and screw d, said plateD having a V-cnt therein,forming a brad,which 50 is driven into said tenon to prevent the plate Dfrom oscillating.

5. The combination,with the sliding bars of extension-tables havinglongitudinal mortises in their engaging surfaces, of the tenon 0, me- 35 tallic plate D, having the downwardly-turned leaves 6 e, and means forsecuring said plate to said tenon.

In testimony that I claim the foregoing as my own I hereunto affix mysignaturein pres; o ence of two witnesses.

THOMAS E. HENNESSY.

Witnesses:

EDWARD W. SOHIRACH, FRANK D. THOMASON.

